JP3292131B2 - Drive transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive transmission device used for an image reading device such as an image scanner or a digital copying machine for reading image information of a document.

[0002]

2. Description of the Related Art In recent years, high-speed reading and high-resolution reading of an image reading apparatus have realized high-speed driving for achieving high-speed reading and low-speed driving for high-resolution reading of a drive transmission device. A comparison is required. Further, the size and cost of image reading apparatuses have been progressing year by year, and the drive transmission device is required to have a high speed ratio and to cope with miniaturization and cost reduction.

[0003] A conventional drive transmission device will be described below. FIG. 4 is a cross-sectional view of an image reading device using a conventional drive transmission device, FIG. 5 is a perspective view of an image reading device using the conventional drive transmission device, and FIG. 6 is a perspective view of main components of the conventional drive transmission device. FIG.

In FIG. 4, reference numeral 1 denotes a frame body of an image scanner main body as an image reading device; 2, an original; 3, a platen glass on which the original 2 is placed; Reference numeral 5 denotes a fluorescent lamp for illuminating the original 2, reference numeral 6 denotes a reflection mirror, reference numeral 7 denotes an image forming lens for forming an optical image, and reference numeral 8 denotes a photoelectric conversion of the light image formed by the image forming lens 7 to an electric signal. C with thousands of elements arranged in one line
CD, 9 is an optical carriage as a moving body integrally formed with the reflection mirror 6, the imaging lens 7, and the CCD 8.

In FIG. 5, reference numeral 10 denotes a rail which supports the optical carriage 9 so as to be able to move linearly, 11 denotes a drive unit, 12 denotes a drive pulley, 13 denotes a transmission belt rotated by the drive pulley 12, and 14 denotes a drive pulley 12 And a driven pulley on which the transmission belt 13 is stretched in cooperation with the pulley.

In FIG. 6, reference numeral 15 denotes a drive motor for generating a rotational force, reference numerals 16 and 17 denote pulleys, and reference numeral 18 denotes pulleys 16 and 1.
A transmission belt stretched between 7 and 19 is a clutch, 2
Reference numeral 0 denotes a shaft connected to the drive pulley 12. When the clutch 19 is energized, the rotation of the pulley 17 can be transmitted to the shaft 20. The pulleys 21, 22, 23, 24 are a pulley 17, a shaft 20 is a pulley 24.
It is connected to. 25 and 26 are between the pulleys 21 and 22,
A transmission belt 28 stretched between the pulleys 23 and 24;
Is a clutch, 29 is a shaft connected to the pulley 23, and the clutch 28 can transmit the rotation of the pulley 22 to the shaft 29 by being energized.

The operation of the conventional drive transmission device configured as described above will be described below with reference to FIGS.

First, in FIG. 4 and FIG.
The reflected light of the document 2 illuminated by the light is reflected by the reflection mirror 6 and is imaged on the CCD 8 by the image forming lens 7, so that the document 2 corresponding to one line of the CCD 8 is read. Here, the entire surface of the document 2 is read by pulling the optical carriage 9 in the direction of arrow A by the transmission belt 13 operated by the drive unit 11.

Here, in order to read the original 2 at high speed, it is necessary to rotate the drive unit 11 at high speed and move the optical carriage 9 at high speed. In order to read the original 2 at a high resolution, the reading time of the original 2 for one line by the CCD 8 is constant. Therefore, by rotating the drive unit 11 at a low speed and moving the optical carriage 9 at a low speed, the original 2 is optically read. It is necessary to read at high density in the moving direction of the carriage 9.

Next, referring to FIG. 6, when the clutch 19 is energized, the rotational force is reduced by the pulley 16, the transmission belt 18, and the pulley 1.
7, the shaft 20 and the driving pulley 12 are decelerated by one deceleration stage by the pulleys 16 and 17. When the clutch 28 is energized, the rotational force is
6, the transmission belt 18, the pulley 17, the pulley 21, the transmission belt 25, the pulley 22, the shaft 29, the pulley 23, the transmission belt 26, the pulley 24, the shaft 20, the drive pulley 12, and the pulleys 16, 17 and the pulley 21 , 2
2 and the pulleys 23 and 24 reduce the speed further by three speed reduction stages.

As described above, by providing the drive motor 15 with two sets of rotational force transmission paths, a speed ratio higher than the changeable speed ratio of the rotational speed of the drive motor 15 itself can be obtained.

[0012]

However, in order to achieve a high speed ratio, in the above-described conventional configuration, the drive unit 11 becomes large and expensive by using a plurality of pulleys, transmission belts, and clutches. There has been a problem that the image forming apparatus is increased in size and cost.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a drive transmission device capable of achieving both high speed ratio and small size and low cost.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a drive transmission device according to the present invention comprises a rotary bearing in which one end is supported by a first bearing and the other end is supported by a second bearing. One possible shaft, a first clutch plate fixed to and rotating with the shaft, a rotation input means mounted at one end of the shaft, and a coaxial relationship with the shaft at the other end of the shaft. A rotation output means rotatably provided with respect to the shaft, a second clutch plate provided on the shaft and rotatable with respect to the shaft and movable along the shaft; A third clutch plate coupled to the second clutch plate and rotatable with respect to the shaft and engaged with the rotation output means; and moving the second clutch plate along the shaft to form the first clutch plate. And the electromagnetic means for engaging, and shift means for engaging is fixed to the shaft for engagement with said second clutch plate when it is released and the second clutch plate and said first clutch plate Wherein said first clutch plate, said second clutch plate, said third clutch plate, said electromagnetic means and said transmission means are all arranged on said shaft between said first bearing and said second bearing. It is characterized by the following.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is characterized in that one end is supported by a first bearing and the other end is supported by a first bearing.
A rotatable shaft supported by a second bearing;
A first clamp fixed to a shaft and rotating with the shaft
A latch plate and a rotation attached to one end of the shaft
Input means, and a coaxial connection with the shaft at the other end of the shaft.
A rotational output provided rotatably with respect to the shaft
Means for rotating the shaft with respect to the shaft provided on the shaft.
Rotatable and movable along the shaft.
A second clutch plate, and the
Rotatable with respect to the motor and engaged with the rotation output means.
The third clutch plate and the second clutch plate
Moving along the shaft to engage with the first clutch plate.
Electromagnetic means for causing the second clutch plate and the first
When the engagement with the clutch plate is released, the second clutch
Transmission means fixed to the shaft engaged with the
Including, the first clutch plate, the second clutch plate, the
The third clutch plate, the electromagnetic means and the transmission means are all
On the shaft between the first bearing and the second bearing
And characterized in that it is arranged in a rotating input means it is coaxial, by performing selectively transfer one of the rotational force of the rotation output means, transmission means and coupling means are all It can be configured coaxially, and has the effect of reducing size and cost.

[0016] The invention described in claim 2 of the present invention is defined by the claims.
1. The drive transmission device according to claim 1, wherein the first clutch plate is
Installed on the shaft between the second clutch plate and the third clutch plate
And is provided in engagement with a protrusion protruding from the shaft.
It is characterized by having.

[0017]

According to a third aspect of the present invention, in the drive transmission device according to the first aspect, the electromagnetic means includes an electromagnetic coil.

[0019]

[0020]

[0021]

[0022]

Hereinafter, embodiments of the present invention will be described. FIG. 1 is a sectional view of a drive transmission device according to one embodiment of the present invention, FIG. 2 is a perspective view of main components of the drive transmission device according to one embodiment of the present invention, and FIG. 3 is one embodiment of the present invention. 1 is a perspective view of an image reading apparatus using a drive transmission device according to the present invention.

Here, the same reference numerals are given to the same components as in FIGS. 4 to 6 showing the conventional drive transmission device, and the detailed description is omitted.

1 and 2, reference numeral 30 denotes a drive unit as a drive transmission device, 31 denotes a drive motor for generating a rotational force, 32 and 33 denote pulleys, and 34 denotes a rotation stretched between the pulleys 32 and 33. Transmission belt as force transmission means,
Reference numeral 35 denotes a shaft, 36 denotes a first clutch plate as a connecting portion, and a pulley 33 and the first clutch plate 36
Is connected to the shaft 35. The pulley 33, the shaft 35, and the first clutch plate 36 constitute a torque input means. Reference numeral 39 denotes a second clutch plate, and reference numeral 40 denotes a third clutch plate rotatably supported by the shaft 35.
The clutch plates 39 are configured so that their tooth shapes mesh with each other between the third clutch plates 40 and are supported so as to be movable in the directions of arrows B and C with respect to the third clutch plates 40 so as to be able to transmit torque. I have.

Further, the second clutch plates 39 are configured so that the tooth shapes of the first clutch plates 36 mesh with each other. Reference numeral 41 denotes an electromagnetic coil, and when energized, the second clutch 39 moves in the direction of arrow B, meshes with the first clutch plate 36, and can transmit torque.

Reference numeral 42 denotes a cam portion which is eccentric to and integrally formed with the shaft 35, 43 denotes a gear which carries out planetary movement around the shaft 35 by circumscribing the cam portion 42, and 44 denotes a coaxial shaft. The internal gear has several teeth more than the gear 43, and the gear 43 performs planetary motion while meshing with the internal gear 44. 45 is a pin provided on the gear 43, 46 is a correction plate as first rotational force output means rotatably supported on the shaft 35, 47 is provided on the correction plate 46, and a pin 45
Is larger in diameter than the pin 45 by the amount of eccentricity of the cam portion 42.

Further, the correction plate 46 is configured so that the tooth shapes of the second clutch plates 39 mesh with each other. The cam section 42, the gear 43, the internal gear 44, and the correction plate 46 constitute a speed change means.

Here, when the gear 43 makes one rotation, the gear 4
The gear 43 rotates by the difference in the number of teeth between the gear 3 and the internal gear 44. Since the gear 43 is in a planetary motion, it is converted by the correction plate 46 into a rotational motion about the shaft 35. Accordingly, assuming that the number of teeth of the gear 43 is a, the number of teeth of the internal gear 44 is b, and the reduction ratio is r, a high gear ratio can be obtained in one stage as shown in (Equation 1).

[0030]

(Equation 1)

Reference numeral 48 denotes a coil spring,
If 1 is not energized to release the engagement between the first clutch plate 36 by moving the second clutch plate 39 in the arrow C direction, and can transmit the rotational force by meshing engagement Ukoto the correction plate 46 . The second clutch plate 39, the third clutch plate 40, the electromagnetic coil 41, and the coil spring 48 constitute a connecting means.

Reference numeral 49 denotes a cylindrical cover, which forms a frame by the internal gear 44 and the cover 49. The shaft 35 is supported by a bearing 50, and the third clutch plate 40 is supported by a bearing 51.
Is rotatably supported.

A driving pulley 52 is rotatably supported by the shaft 35, and engages with the third clutch plate 40 at the concave and convex portions so as to transmit a rotational force.

A sheet metal 53 supports the drive motor 31 and the drive transmission device in parallel and is fixed to the frame 1 (FIG. 3).

The operation of the drive transmission device configured as described above will be described below with reference to FIGS.

First, referring to FIG.
When 1 is energized, the second clutch plate 39 moves in the direction of arrow B and is disengaged from the correction plate 46 and connected to the first clutch plate 36, so that the rotational force is reduced by the pulley 32, the transmission belt 34,
Pulley 33, shaft 35, first clutch plate 36, second
Clutch plate 39, third clutch plate 40, drive pulley 52
And the speed is reduced by one speed reduction step by the pulleys 32 and 33.

In FIG. 1B, the electromagnetic coil 4
1 is not energized, the second clutch plate 39 is moved in the direction of arrow C by the coil spring 48 and disengaged from the first clutch plate 36 to be coupled to the correction plate 46, thereby reducing the rotational force of the pulley 32. , Transmission belt 34, pulley 3
3, the shaft 35, the gear 43, the correction plate 46, the second clutch plate 39, the third clutch plate 40, and the drive pulley 52 are transmitted to the pulleys 32 and 33, the cam portion 42, the gear 43, the internal gear 44, and the correction plate. The speed is further decelerated by deceleration by the speed change means by 46.

As described above, in the present embodiment, the cam portion 4
2, transmission means including a gear 43, an internal gear 44, and a correction plate 46; coupling means including a second clutch plate 39, a third clutch plate 40, an electromagnetic coil 41, and a coil spring 48; and a first clutch plate 36. By configuring all the components coaxially on the shaft 35, a simple configuration is achieved, and it is possible to achieve both high speed ratio, small size, and low price.

Further, since the unit is surrounded by a frame composed of the internal gear 44 and the cover 49, the unit can be formed, and the assembling property is improved, thereby reducing the cost.

[0040]

As described above, according to the present invention, a high speed ratio can be ensured, and both small size and low cost can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a drive transmission device according to an embodiment of the present invention.

FIG. 2 is a perspective view of main components of the drive transmission device according to the embodiment of the present invention.

FIG. 3 is a perspective view of an image reading apparatus using the drive transmission device according to one embodiment of the present invention;

FIG. 4 is a cross-sectional view of an image reading apparatus using a conventional drive transmission device.

FIG. 5 is a perspective view of an image reading apparatus using a conventional drive transmission device.

FIG. 6 is a perspective view of main components of a conventional drive transmission device.

[Explanation of symbols]

 31 Drive motor 33 Pulley 34 Transmission belt 35 Shaft 36 First clutch plate 39 Second clutch plate 40 Third clutch plate 42 Cam portion 43 Gear 44 Internal gear 46 Correction plate 47 Electromagnetic coil 48 Coil spring 49 Cover 52 Drive pulley

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-1846 (JP, A) JP-A-3-244852 (JP, A) JP-A-5-180338 (JP, A) 151 (JP, U) JP-B No. 34-2801 (JP, B1) U.S. Pat. No. 2533056 (US, A) U.S. Pat. No. 3,430,521 (US, A) U.S. Pat. 58) Surveyed field (Int.Cl. ⁷ , DB name) F16H 37/02 F16H 3/70

Claims (3)

(57) [Claims] A rotatable shaft supported near a first end by a first bearing and supported near a second end by a second bearing, and a first rotatable shaft fixed to the shaft and rotated together with the shaft. A clutch plate; rotation input means attached to one end of the shaft; rotation output means provided at the other end of the shaft so as to be rotatable with respect to the shaft in a coaxial relationship with the shaft; A second clutch plate rotatable with respect to the shaft and movable along the shaft; and a rotation output means coupled to the second clutch plate and rotatable with respect to the shaft. a third clutch plate being engaged with an electromagnetic means for engagement with said first clutch plate to said second clutch plate is moved along the shaft, the said second clutch plate first clutch Transmission means fixed to the shaft that engages with the second clutch plate when disengagement with the first clutch plate, the second clutch plate, the third clutch plate, A drive transmission device in which electromagnetic means and said transmission means are all located on said shaft between said first bearing and said second bearing. 2. The method according to claim 1, wherein the first clutch plate is provided on the shaft between the second clutch plate and the third clutch plate, and is provided in engagement with a protrusion protruding from the shaft. The drive transmission device according to claim 1, wherein: 3. The drive transmission device according to claim 1, wherein said electromagnetic means includes an electromagnetic coil.